Controlled thermonuclear reactor experiments, and many accelerator based neutron generators, use the fusion reaction of deuterium and tritium nuclei. Efficient operation of these devices demands the removal of helium-4 as a reaction product and helium-3 as a decay product of the radioactive isotope tritium. Known methods for accomplishing such removal include the principles of chemisorption and desorption with the use of hydride-forming metals and the diffusion of hydrogen through metals like palladium. The former methods sacrifice a significant part of the hydrogen inventory and the latter methods require pressures far above the typical operating pressures of controlled thermonuclear reactors and neutron generator devices. Also, a major fraction of the total gas inventory must be treated to make removal of these impurities possible.